Overview
This integrated unit teaches explicit estimation skills through examining environmental issues at our school site. The overall goal for the unit is for students to make sense of statistical reporting and very large numbers through evaluating use and waste habits of the school community. By using estimation techniques and manipulating quantities, students will be able to evaluate quantities over 1000. Beyond recognizing large numbers and understanding their value, these techniques will also provide them with the skills necessary to multiply and add large numbers and evaluate their own multiplication and addition processes to see if their solutions are reasonable. Besides merely recognizing and computing large numbers, students will be able to use estimation and relative place value to compute quantities of length, area and volume using various units of measurements.
In fourth grade a great deal of mathematical instruction is focused on the processes of long multiplication and division. Research shows, and testing increasingly requires, that best practices in mathematics instruction include teaching students to write about their mathematical thinking, explain their process, and evaluate their solution. Performing algorithms will no longer suffice. Evaluation of the reasonableness of solutions is critical in teacher evaluation and student self reflection of their processes to determine what is taking place; Is there a computational error? Are students using an algorithm correctly? More importantly, do students understand the basic premise behind the algorithm they are using? One of the goals, therefore, in this exercise, is to teach students estimation techniques (focusing on order of magnitude and relative place value) to evaluate their own processes and errors to determine the reasonableness of their solutions when applying new computation strategies to increasingly larger numbers.
These same principles apply to the teaching of measurement, an essential skill that is often relegated to the back of the book, the end of the pacing guide, and consequently left out of yearly cycles due to a lack of time. The teaching of measurement can be embedded in many other topics if we ask the right questions: What is the context of the problem? What kind of solutions are we looking for? How will we measure and report our results?
In order to reach these goals, I will have my students examine the problem of the amount of waste that is generated in our school cafeteria. Most of my students, young as they are, share their parent's vocal concern for the environment and affection for current "green" trends governing use and misuse of resources in the community. The school is actively recycling and is hoping to receive a grant to place solar panels on the roof to offset coal generated electricity use. These are big issues, and I would like to study them with my students in a context that is tangible and prevalent in our daily life - lunch.
The companion piece to the mathematical component of the unit would be to examine the environmental impact of these quantities, a socially important lesson which meets multiple social studies and science standards. Students would learn about the waste cycle from usage to landfill as well as the various alternatives that are available in our community, such as recycling. A natural follow up to the unit would be to examine alternatives to the current materials being used and analyze those statistics in order to make an informed evaluation of the costs and benefits of potential changes, such as rewashing plastic trays, which consumes water (a scarce resource in our community), and biodegradable disposables, which are more costly to purchase and require community buy-in to manage. Eventually, I would hope to apply the model to examining other waste vs. conservation situations. Other extensions would be for students to develop their own examinations of their environment, and hopefully their own campaigns for environmentally and socially responsible choices in the school community.
Comments: